Disable ptype/o for dynamic types
Commit Message
A user pointed out that "ptype/o" of a certain Ada type -- while in C
mode -- caused gdb to crash.
The bug here is that dynamic types can't really be printed this way.
This patch avoids the bug by disabling the "/o" feature in this case.
Note that using "ptype/o" in this way makes sense for the time being,
because the Ada code doesn't support the "/o" feature (yet); and in
any case gdb should not crash.
---
gdb/testsuite/gdb.ada/ptype-o.exp | 47 ++++++++++++++++++++++++++
gdb/testsuite/gdb.ada/ptype-o/prog.adb | 29 ++++++++++++++++
gdb/typeprint.c | 6 ++++
3 files changed, 82 insertions(+)
create mode 100644 gdb/testsuite/gdb.ada/ptype-o.exp
create mode 100644 gdb/testsuite/gdb.ada/ptype-o/prog.adb
Comments
On 1/11/23 13:42, Tom Tromey via Gdb-patches wrote:
> A user pointed out that "ptype/o" of a certain Ada type -- while in C
> mode -- caused gdb to crash.
>
> The bug here is that dynamic types can't really be printed this way.
> This patch avoids the bug by disabling the "/o" feature in this case.
>
> Note that using "ptype/o" in this way makes sense for the time being,
> because the Ada code doesn't support the "/o" feature (yet); and in
> any case gdb should not crash.
LGTM:
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Simon
new file mode 100644
@@ -0,0 +1,47 @@
+# Copyright 2023 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Test that ptype/o of a dynamic type does not crash.
+
+load_lib "ada.exp"
+
+if { [skip_ada_tests] } { return -1 }
+
+standard_ada_testfile prog
+
+foreach_with_prefix scenario {all minimal} {
+ set flags [list debug additional_flags=-fgnat-encodings=$scenario]
+
+ if {[gdb_compile_ada "${srcfile}" "${binfile}-${scenario}" executable $flags] != ""} {
+ return -1
+ }
+
+ clean_restart ${testfile}-${scenario}
+
+ set bp_location [gdb_get_line_number "BREAK" ${testdir}/prog.adb]
+ runto "prog.adb:$bp_location"
+
+ gdb_test "set lang c" \
+ "Warning: the current language does not match this frame."
+
+ if {$scenario == "minimal"} {
+ set exp "ptype/o does not work with dynamic types.*"
+ } else {
+ # In "all" mode this prints nonsense, but at least does not
+ # crash.
+ set exp ".*"
+ }
+ gdb_test "ptype/o struct prog__rec" $exp
+}
new file mode 100644
@@ -0,0 +1,29 @@
+-- Copyright 2023 Free Software Foundation, Inc.
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+procedure Prog is
+ type Index is range 0 .. 31;
+ type Char_Array is array ( Index range <>) of Character;
+
+ type Rec (Length : Index) is
+ record
+ TV_Description : Char_Array (1 .. Length);
+ Note : Char_Array (1 .. Length);
+ end record;
+
+ X : Rec (7);
+begin
+ null; -- BREAK
+end Prog;
@@ -539,6 +539,12 @@ whatis_exp (const char *exp, int show)
type = value_type (val);
}
+ if (flags.print_offsets && is_dynamic_type (type))
+ {
+ warning (_("ptype/o does not work with dynamic types; disabling '/o'"));
+ flags.print_offsets = 0;
+ }
+
get_user_print_options (&opts);
if (val != NULL && opts.objectprint)
{